welcome to LQ.org!!!
at the root@darkstar:~#
type startx and it should take you into a window manager...probably KDE.
you can also type xwmconfig and choose from a list of window managers, and after clicking one, type startx and that one will open.
darkstar is the default name slackware gives when installed, if you don't supply one while you're installing it.
also, you might wanna check out the slackware site
, especially the book part. lots of helpful info there.
slackware boots into text mode, and you log into a gui using startx. you can use gdm or kdm for a graphical login...the slack site or this site has lots of info on how to use it. i don't use the graphical login, so i can't help you there...